Switching valves are used in various types of hydraulically operated systems for changing connections to pressure and return during or at the end of an operational cycle. One type of system that employs switching valves is a drive and control system for a reciprocating floor conveyor. An example of a hydraulic drive and control system for a reciprocating floor conveyor is disclosed in my U.S. Pat. No. 5,193,661, issued Mar. 16, 1993 and entitled "System of Linear Hydraulic Motors". The disclosed conveyor is of a type in which each of three sets of floor slats is connected to a respective drive motor. The three drive motors are operated to move the floor slats simultaneously in a first conveying direction and then to move the slats sequentially in the opposite direction and thereafter repeat the cycle until the conveying operation is completed. The disclosed system has a switching valve for alternately supplying pressure to opposite ends of the motors to cause movable portions of the motors to move in the two directions. My U.S. Pat. No. 5,103,866, granted Apr. 14, 1992, discloses a valve which may be used as a switching valve in a drive and control system for a reciprocating floor conveyor and which has a control rod that is mechanically operated by contact with abutments carried by the motors or members connected thereto.
Drive and control systems for reciprocating floor conveyors typically have means for controlling the direction of operation of the drive motors to convey a load in either of two opposite directions. An example of a directional control valve is the one disclosed in my U.S. Pat. No. 5,361,679, granted Nov. 8, 1994. This valve is also shown in my U.S. Pat. No. 5,375,619, granted Dec. 27, 1994.